“Nicotine patches and nicotine gum, intended to wean smokers from their dangerous habit, actually seem to encourage teenagers to take the first puff, for reasons that any economist might have predicted. Since there are now products to help smokers quit, it becomes less risky, as a purely rational proposition, to pick up the habit.”

Steven E. Landsburg makes a related point his entertainingly contrarian The Armchair Economist (Free Press, 1995), a book that with a catchier title might have become the Freakonomics of its day. In a chapter semi-facetiously called “How Seat Belts Kill,” Landsburg describes what happened in the 1960s when federal legislation for the first time required Americans to wear seat belts:

“The number of auto accidents increased. The reason is that the threat of being killed in an accident is a powerful incentive to drive carefully. But a driver with a seat belt and a padded dashboard faces less of a threat. Because people respond to incentives, drivers are less careful. The result is more accidents.”

Landsburg goes on:

“An interesting question remains. How big is the effect in question? How many additional accidents were caused by the safety regulations of the 1960s: The regulations tend to reduce the number of driver deaths by making it easier to survive an accident. At the same time, the regulations tend to increase the number of driver deaths by encouraging reckless behavior. Which effect is greater?”

In the mid-1970s, University of Chicago researcher Sam Peltzman studied the question and found that two effects were of about the same size and cancelled each other out, Landsburg says:

“There were more accidents and fewer diver deaths per accident, but the total number of deaths remained essentially unchanged. An interesting side effect appear to have been an increase in the number of pedestrian deaths; pedestrians, after all, gain no benefit from padded dashboards.”

“Late Night With Jan Harayda” is an occasional series of posts about books that appear after 10 a.m. Eastern time that may include commentary but do not include reviews, which typically appear earlier in the day.